Electrical connectors provide a means for coupling electrical circuits at selected locations. The connectors are in the form of separate connector portions which are mated for coupling together. One connector portion contains a cluster of discrete elongated pins to which individual circuits are terminated. The other connector portion contains a cluster of discrete conducting receptacles which are terminated to additional circuits. When the connector portions are mated the pins are pluggably received in corresponding receptacles to complete electrical circuits through the connector portions. The mating connector portions are of fixed design to enable standardization whereas the cluster arrangement of the pins and receptacles may be varied to adapt the standardized connectors for use in a variety of circuit configurations. It has now been found desirable to provide filtering of selected circuits for example to isolate these circuits from undesired EMI/RFI interferences or to provide a pass band frequency for a circuit. Incorporating the necessary filter structure within the standardized connector has been a problem due to limitations in size, available space and packaging techniques.